The Environment of the Invention
This invention preferably is embodied in an accessory device for swimming pool skimmers.
A swimming pool skimmer is a device which is mounted in the wall of a swimming pool adjacent the free surface of the water in the pool. The principal function of a skimmer is to remove leaves and other floating debris from the pool surface as the pool water circulation system is operated; the skimmer is a component of the circulation system.
A swimming pool water circulation system includes the pool itself, a motor driven pump, a flow duct from the pool to the inlet or suction side of the pump, a return flow duct from the discharge or pressure side of the pump to the pool, and a filter unit in the return flow duct. If desired, a water heater can be installed in the return duct. The filter is of the kind which removes sand, dust and other finely divided solid matter from water passed through it. Pool filters are not well suited for the removal from water of larger things such as leaves, flower petals, pine needles and the like. Therefore, it is now common to equip swimming pools with skimmers for the removal from water entering the return flow duct to the pump of leaves and the like, which things often float on the surface of the pool.
While skimmers are manufactured by many firms, they now generally have a common design philosophy. A typical skimmer, according to prevailing design philosophy, defines a vertically elongate chamber which has a lower basket portion, a central plenum portion, and an upper chimney portion which is closed by a removable cover. A foraminous basket, having a selected pore size, is supported across the top of the basket cavity so the bottom of the basket is above the bottom of the cavity. A throat extends laterally from the plenum to a principal inlet opening to the skimmer; that opening is square or rectangular and is defined in a vertical plane. A coupling for a flow pipe, and often two such couplings, is located at the bottom of the basket cavity of the skimmer. The skimmer is built into the pool so that the throat inlet opening is centered at the optimum water level in the pool, which level normally varies one to two inches or so above and below the optimum level; the opening is sufficiently high to encompass this range of water levels. The cover for the skimmer chimney is placed flush with a deck of other surface around the pool. The throat is partially submerged if the pool is properly filled, and so the skimmer basket cavity and the lower part of the plenum are filled with water when the pool is filled.
The flow duct from the pool to the suction side of the pool circulation pump is connected to the bottom of the basket cavity. When the pump is operated, it takes in water from the skimmer. The water enters the skimmer from the pool through the throat, carrying with it leaves and the like which float on the water surface in the civinity of the throat opening. Water entering the skimmer via the throat passes through the basket where the leaves and other large things are strained out by the basket. Thus, water passing to the pump is free of large pieces of debris, and the filter is better able to do for longer periods the task assigned to the filter. Debris collected in the skimmer basket is easily dealt with by removing the skimmer cover, removing the basket via the chimney, emptying the basket of collected debris, and replacing the basket.
It is also common, if not now prevailing practice, to locate a buoyant bottom-pivoted weir gate across the skimmer throat. The gate swings to and fro in response to waves in the pool, yet allows water and debris to pass over it into the skimmer, but not to pass from the skimmer back to the pool. Thus, the weir gate enhances the skimming action of the skimmer.
In many, perhaps most, of the skimmers now manufactured, a second flow connection is provided to the bottom of the skimmer body. The second connection is a main drain connection from which a pipe extends to a drain opening in the lowermost part of the pool. This connection, among other things, assures that the lower portion of the basket cavity will be filled with water even if the pool level falls somewhat below the skimmer throat, and thus the pump cannot lose its prime; it also affords a means of pumping the pool dry if need be. If such connection exists, there can be flow through it to the skimmer when the skimmer operates during periods when the pump is operated.
It is also known to provide water-powered cleaning devices for swimming pools. Such devices can be of the kind operated by pressurized water, such as automatic devices which float on the water surface or move across the bottom of the pool. Such devices receive water from the discharge side of the circulation pump, as by coupling to a port into the pool from the circulation pump, or water supplied by an auxiliary pump installed specifically to power the cleaning device. Such pressure-side cleaning devices operate to agitate the pool water, thereby to place dirt and debris in suspension for removal by the pool skimmer and filter units.
Pool cleaning devices which operate on pump suction are also known; they include vacuum heads which are coupled to long poles and moved manually across the pool bottom, and they also include automatic devices which move across the pool bottom--the former are used for short periods, whereas the latter can be operated for long periods measured in hours or days. Such devices are coupled by flexible suction hoses to the circulation pump inlet via the pool skimmer; they operate to suck from the pool bottom accumulations of dirt, leaves and the like, and to introduce them to the pool filter for removal there. It is the latter class of pool cleaning devices with which this invention is cooperable; more particularly, this invention has greatest utility with suction-side automatic pool cleaners, while also being useful with manually controlled cleaners such as vacuum heads.
As noted, suction-side pool cleaners are operated by connection to the suction-side of a pool circulation pump by connection of a suction hose to the pool skimmer. The suction hoses commonly used, while flexible, are not readily bent sharply at right angles. Therefore, such hoses are coupled to the pool-to-pump return line via the skimmer through the top of the skimmer, i. e., through the skimmer chimney upon removal of the chimney cover; such connections are made either after removal of the skimmer basket (in which case the coarse straining function of the basket is lost) or to special connections inside the skimmer which preserve the function of the basket. In other instances, the hose may be connected to a special port defined adjacent the skimmer throat opening in a side wall of the pool; this can be done where a specially designed skimmer was or is built into the pool, in which case a skimmer accessory according to this invention is not so useful. However, very few pool skimmers having such special hose connection features now exist. Thus, the usual situation, addressed by this invention, involves a typical skimmer, as described above.
Where the suction-side pool cleaning device is a vacuum head moved manually across the pool bottom, it is not overly hazardous to connect the cleaning suction hose to the skimmer through the skimmer chimney. This is because such cleaners are used for short periods, it is apparent they are being used, and so the presence of an open chimney and a hose extending out of the pool and over the pool edge to the chimney are hazards which can be accepted and warned against. Even so, the skimmer is disabled from skimming and coarse straining during such periods. A more serious set of circumstances exist where the suction-side cleaning device is an automatic device whose proper and effective use requires connection to the skimmer for hours or perhaps days. In such cases, the open chimney and the exposed hose over the pool edge can be serious hazards. Also, it is undesirable to forego the benefits of a skimmer weir gate and strainer basket for extended periods, especially the latter.
Thus, a need exists for equipment which can be used readily and conveniently with existing conventional skimmer structures, of which there are many thousands in place, to overcome the hazards and functional limitations which otherwise exist when an automatic suction-side pool cleaner is in use. This invention addresses and fills that need.